1. Field of the Invention
The present invention relates generally to the field of materials technology and more particularly to a solder composition having improved thermal and electrical properties and a method for manufacturing the same.
2. Description of the Related Art
In any circuit involving electrical power, a major design objective is to reduce the temperature of the components, improve reliability, reduce cost, and improve operation. Many integrated circuits (“ICs”)—including, for example, dual in-line plastic packaged ICs—have shapes not conducive to fastening directly to the chassis. The packaging method for an IC becomes a limiting factor, as the package serves the function of carrying high current densities in addition to high thermal loads.
In some cases, the design limit of the package becomes the interfaces between the IC and the package, which is itself limited by the manufacturing technique used. A reason for this is that the interface materials best suited for good performance are those that posses both high electrical and thermal conductivity (such as copper or gold). However, these material also have melting points well beyond the manufacturing temperatures that can be tolerated for the IC. Thus, lower melting point solders are typically used to make the interface joint. But these solders do not have an ability to move heat and electrons as well as the interface materials themselves and thus limit the performance potential of the package. There remains a need in the art for a solder joint with improved electrical and thermal conductivity and a melting point low enough to prevent damage to the IC during soldering.
By reducing the thickness of the solder layer, conductive performance is improved. The thickness of the solder layer is limited by the tolerance of the IC and package in addition to the manufacturing method used. Thus, there remains a need in the art for a solder joint that can provide minimal solder thickness for IC applications.